Spectral separation technology is an advanced stereoscopic display technology implemented in a 3D display device.
A 3D display apparatus comprises: a display light source, the display light source uses two or more groups of laser light sources which are spectral separated, and laser beams of the same color emitted from different groups of laser light sources have different peak wavelengths. In an example where two groups of laser light sources are used, each group includes three monochromatic lasers, i.e. a red laser, a blue laser and a green laser, and laser beams emitted by two monochromatic lasers of a same color from the two groups of laser light sources have different peak wavelengths. At this time, two red lasers emit red laser beam 1 and red laser beam 2 respectively, two green lasers emit green laser beam 1 and green laser beam 2 respectively, two blue lasers emit blue laser beam 1 and blue laser beam 2 respectively. There is no spectral overlap between the two groups of laser light sources. An image formed by the red laser beam 1, the green laser beam 1 and the blue laser beam 1 enters into one human eye, and an image formed by the red laser beam 2, the green laser beam 2 and the blue laser beam 2 enters into the other eye, thereby forming a three-dimensional image. A pair of narrow band filter glasses receives the red laser beam, the green laser beam and the blue laser beam after spectral separation. The main difference of the spectral separation stereoscopic imaging technology from conventional stereoscopic imaging technology is that by using spectral separation, the left eye image and the right eye image can be separated highly. The image is separated based on wavelengths of light of different colors, without any signal conversion process, thus the spectral separation stereoscopic imaging technology is also known as passive stereoscopic imaging. Compared to conventional stereoscopic imaging technology, the spectral separation display technology has the following advantages: 1, the pair of the left eye image and the right eye image are strictly filtered and separated highly, so that no ghost image appears when viewing stereoscopic image by wearing glasses; 2, the image quality is good and flicker-free, the wearer is comfortable and does not feel dizzy in durable watching; 3, the glasses do not require battery and complex circuitry, thus have lightweight and better comfort; 4, no signal synchronization emitter is required, the head can move freely, the wearers do not interfere with each other, thus the technology can meet the occasions having lots of spectators.
The inventors found that at least the following problems exist in the prior art: a group of monochromatic laser is required to generate a group of laser light source; take the above 3D display device for stereoscopic display as an example, in short, two groups of laser light sources emit six monochromatic laser beams (i.e. the red laser beam 1 and red laser beam 2, green laser beam 1 and green laser beam 2, blue laser beam 1 and blue laser beam 2), six monochromatic lasers in total are required; that is, each monochromatic laser emit a laser beam having a peak wavelength. Therefore the 3D display device has large volume and high cost.